Japanese Patent Disclosure No. 55-115773 (Japanese Pat. Application No. 54-22445) discloses a manual sweeping copier whose main body is moved, thereby to copy an original. More specifically, while the copier is being manually swept, an optical element reads image data from the original. The image data is converted into digital data and written into a memory. The image data is read from the memory and is printed, thus copying the original.
The reading width of the small-sized copier disclosed in Japanese Patent Disclosure No. 55-115773 is determined by the width of the optical element, and the reading length of the copier is inevitably limited by the memory capacity of the memory. Therefore, even if the copier reads an image from an original having a width less than the reading width of the copier, it reads image data over the entire reading width. Consequently, the memory may become full before the copier is reads all image data from the original.